Used T23G, can't factory reset, can't update

[Yisroel_MongoTEL]

(05-19-2020 05:31 PM)MonkeySeeMonkeyDo Wrote:  I bought a used T23G, I boot it up and it is provisioned and working... I factory reset the phone I am able to login to the web interface with the default credentials. I update to the latest firmware, the phone restarts, the firmware did not update (same version as before) and the phone reconnects back to the old provisioned customer.

I have no idea what is going on. I have no factory reset it from the phone, and from the web interface, but at the end it always goes back to the old provisioned settings.

Any recommendations to try?
TIA

What's the firmware version (might be some vendor-specific firmware)?

Another possible reason is that it is on Yealink's RPS system added by the previous provider/customer. For that, you'll need to open a ticket with Yealink (ticket.yealink.com) and after proving ownership they'll remove it.